This invention relates to a light-sensitive silver halide color photographic material, more particularly to a light-sensitive silver halide color photographic material using a novel two-equivalent yellow coupler which can be manufactured inexpensively and is excellent in activity, color reproducibility and image storage stability, high in solubility in low-boiling point and high-boiling solvents used for dispersing a coupler, and further excellent in dispersion stability.
In recent years, in light-sensitive silver halide color photographic materials (hereinafter sometimes called merely light-sensitive color materials), two-equivalent couplers in which an suitable substituent is introduced to a coupling position (active point) of a coupler which reacts with an oxidized product of a developing agent so that only 2 atoms of silver for forming one molecule of a dye are required have been employed frequently in place of conventional four-equivalent couplers which require 4 atoms of silver for forming one molecule of a dye. However, requirements of a coupler have become more strict with the progress of light-sensitive color materials. Not only improvement in activity but also further improvement in color reproducibility, image storage stability, solubility in low-boiling point and high-boiling point solvents and dispersion stability have been demanded.
As techniques for improving color reproducibility and activity, there has been known a yellow coupler having a heterocyclic compound with a cyclic imide structure as an eliminatable group and having an alkoxy group introduced to the 2-position of anilide portion For example, in Japanese Unexamined Patent Publication No. 115219/1977, there is disclosed a yellow coupler having an alkoxy group at the 2-position of anilide portion and having a hydantoin group or an urazol group as an eliminatable group. However, this coupler involves a drawback that light-resistance is extremely poor due to sulfamoyl group existing as a ballast group.
As techniques for improving light-resistance while maintaining good color reproducibility and high activity, there have been known, for example, yellow couplers having an alkoxy group at the 2-position and an acylamino group at the 5-position of anilide portion as disclosed in Japanese Unexamined Patent Publication No. 123047/1988. However, since these couplers have poor solubility in low-boiling point solvents such as ethyl acetate and high-boiling point solvents such as dibutyl phthalate, there involve such an inconvenience in manufacturing light-sensitive color materials that a large amount of a solvent should be used for dispersion, and further a drawback that these couplers are liable to be precipitated after dispersion in the above solvents. Under the present circumstances where thin film formation has been strongly demanded, it is apparent that these drawbacks are extremely emphasized and become a serious obstacle to practical use. Further, the coupler disclosed in said publication has a characteristic that a sulfonyl group is contained in a ballast group. For introducing this sulfonyl group, its manufacturing steps become complicated, and therefore there also involves a drawback that manufacture cost becomes expensive.
In Japanese Unexamined Patent Publications No. 6341/1975, No. 125140/1991 and No. 125141/1991, there are disclosed yellow couplers having an alkoxy group at the 2-position of anilide portion, a hydantoin group as an eliminatable group of which the 5-position is substituted by an alkyl group, and a straight unsubstituted alkylcarbonylamino group at the 5-position of anilide portion. In these couplers, since a ballast group is derived from an unsubstituted alkylcarboxylic acid, manufacture cost can be reduced, and further color reproducibility, light-resistance, solubilities in low-boiling point solvents and high-boiling point solvents such as dibutyl phthalate and dispersion stability are improved. However, since these couplers have activity slightly lowered due to an alkyl group existing at the 5-position of a hydantoin group which is an eliminatable group, they cannot satisfy the recent demand for heightening activity sufficiently.
In Japanese Unexamined Patent Publication No. 165145/1981, there is disclosed a yellow coupler having an alkoxy group at the 2-position of anilide portion, a urazol group as an eliminatable group and a substituted alkylcarbonylamino group at the 5-position. However, it has been found that this coupler is inferior in activity because the urazol group is unsubstituted and hydrophobicity of substituted components of the ballast group is too high.